Dynamo-electric machine.



J. J. WOOD.

DYNAMO ELECTRIC MACHINE.

APPLIOLTIOK FILED 110V. 22, 190'].

Patented Apr. 27, 1909.

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Patented Apr. 27, 1909.

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J. J. WOOD.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED NOV. 22, 1907. 919,51 1

INK/ENTER JAMES J 1/1/0017.

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JAMES J. WOOD, or FORT WAYNE, INDIANA.

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To all whom it may concern: Be it known that I, JAMES J. W001), a cit1- zen of the United States, residin at Fort Wayne, county of Allen, State of Indiana,

speed there is a large' c entrifugal force acting on the field magnets, and by my method of clamping them in place great mechanical strength in a tangential direction is secured 1 because of the large surface of contact of the retaining means. The electrical advantage possessed by my construction is its low magnetic reluctance due to the fact that the olepieces are not cut out in the center, as eretofore, and that the magnetic path is entirely through steel, as will be hereafter explained.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, however, and other advantages possessed by it, reference may be had to the following description taken in connection with the accompanying drawing, in which- Figure 1 is asection through a portion of a revolving field alternator embodying my invention; Fig. 2 is a view of a portion of a field spider having the field magnets mounted thereon in accordance with my invention, one of the field windings being in section; Fig. 3 is a section on the line 33 of Fig. 2 looking in the direction of the arrows, and Fig. 4 is a section on the line 44 of Fig. 2.

Referring now to the drawing, the frame 1 is split in the center, and the bolts 2 holding the frame together pass through the punchings 5. The armature winding 6 is embedded in slots in the laminations 5. The field magnets are held in place on the s ider 8, which may have central arms 9 wit mycclinstruction for holding the magnets in p ace.

The laminae 10 of the field poles have tips 11 overhanging the field coils 7, and indentations 12 into which the wedge-shaped retaining pieces. 13 for the field magnets fit. These retaining portions are preferably made of Specification Letters Patent. Application fled November 82,1907- Serial No. 408,818.

. Patented April 27, 1909.

steel and are fastened to the field spider by means of bolts 14. The laminae 10 of the field poles are clam d between end members 15 by rivets 16, t e-heads 17 of which are countersunk in the end members. These end members have longitudinal air passages 18in them, so'that by the revolution of the machine air is set. in motion and passes through these passages in the direction of the arrows, cooling the end laminae and the field and armature windings.

The field windi 7-is wound upon a s ol 20in any prefer-re manner. In assemb g the spool upon the field poles I first place the brass collar 21 upon the polepieces, then the wound s 001 20, and then a second brass collar 22. hese brass collars have grooves 19, and are forced upon the field poles under a screw ress, causin the ed es of the metal to bend ack and re ucing t e dimension of the grooves as shown. This method of forcmg on the brass collars has the'advanta e that it avoids the filin of the collars to t and that the edges of 51c metal against the pole is under compression and consequently makes a very tight fit.

To assemble the field magnets upon the spider, I prefer to bolt the wedge-shaped retaining pleces 13 loosely on the spider 8, then move the field magnets into axially extending ooves 23 on the rim of the spider, the

retaming pieces entering the indentations 12.

vWhen the magnets are in their proper position the bolts 14 may be tightened so as to firmly hold them there.

The advantages of my retaining means for the field magnets are manifold. By structing the wedge-shaped pieces 13 of steel the entirepath of the magnetic flux is through steel, the cast-iron spider being a path in parallel with the retaining pieces; This construction also adapts itself. perfectly to changing the-air gap 24 by inserting shims under the pole ieces, and this is done without increasing the magnetic reluctance of the circuit for the same 'reason as above. Further, the oles can be removed from the-machine'wit out removing the bolts and retainmg pieces by simply loosening the latter.

'However, my retaming pieces 13 may. be

made of other metal, or may be a laminated structure.

What I claim as new, and desire to secure by Letters Patent of the United States, is, 1. In a dynamo-electric machine, a spider, pole pieces having indentations, a retaining conpole pieces, and means for clamping said retaming pieces to said spider thereby holding said ole pieces m place.

2. a dynamo-electric machine, a spider, laminated pole pieces, each lamina having similar indentations on both sides thereof, a retaining piecefitting in said indentations in adjacent ole pieces, and means for clamping said retaining ieces to said spider thereby holding said po e pieces in place. I

3. In a dynamo-electric machine, a spider, laminated pole pieces, each lamina similar indentations'on both sides thereof, a steel retaining piece fitting in said indentations, and means .for clamping said retaining pieces to said spider thereby holding sai pole in place.

4. a dynamo-electric machine, a spider, laminated pole pieces, each indentations .on both sides thereof, a step wedge-shaped retaining piece. fitting in said vmg having indentationaand bolts clamping said retaining pieces to said spider thereby holding said p e ieces in place. I

a dynamo-electric 'machme, a spider s, laminated pole pieces having indentations 1'2, wedge-shaped ret ieces 13 fitting in saidmdentations, and 0 ts 14 clamping said retaining piedces to said spider, substan- 'tially as descn 6. A field magnet comprising a pole iece,

a brass collar mounted thereon saidrass collar being forced upon the pole piece and ooves near t e inner edge, the inner edges 0 the brass collar being under compression and fitting tightly against the pole piece, substantially as described. V

In witness whereof, I have hereunto set my hand this 15th day of November, 1907.

JAMES J. WOOD.

Witnesses: i

W. H. Gammon, F. S. Hmrrme. 

